9/28/2025
Earlier this month, Apple introduced the new Apple Watch Series 11. With it comes Apple’s most comprehensive set of health features yet, ready for release in over 150 countries on Apple Watches Series 9 and newer. One feature in particular–hypertension monitoring–has been gaining special attention since its debut. This is for good reason: nearly 50% of all U.S. adults have high blood pressure, a condition linked to heart attacks, strokes, kidney disease, and dementia. Globally, over 1 billion people are affected by hypertension, and yet an estimated half of those suffering go undiagnosed and untreated.
With the rapid rise in the use of wearable health devices (such as Apple Watches, Fitbits, and Oura Rings), built-in hypertension detection has great potential to aid in earlier diagnoses, preventing the health- and life-threatening complications that can arise from unchecked high blood pressure.
Apple’s hypertension detection system has even been cleared by the FDA as an effective medical device as of September 11, 2025. However, as stated in one 2023 article examining the impact of wearables on patient well-being, published by the Mayo Clinic, “evidence of efficacy does not mean an absence of harm.” It is important to be upfront about the potential risks of a technology as it’s deployed to hundreds of millions of people around the world, rather than just emphasizing its benefits.
Apple Watches do not actually measure the wearer’s blood pressure; instead, Apple is applying AI models to existing sensor data to predict patterns of hypertension. The optical sensor on the back of the watch collects data on how blood vessels in the wrist respond to the heart’s pumping, which is then fed into an AI model that can detect signs of hypertension.
This method of hypertension detection is not unique to Apple and falls under a growing category of cuffless devices used to monitor blood pressure. Although the FDA has approved many such devices, they are relatively new and, as such, have limited evidence to prove their reliability. Additionally, there is currently no defined protocol for testing cuffless device accuracy, which makes it difficult to get an objective measure of their performance. Because of this gap in scientific understanding of their reliability, cuffless devices are not currently recommended by healthcare professionals.
Additionally, there is some concern that cuffless monitoring methods may cause unintended psychological harm and even potentially overburden the healthcare system. There is a precedent for wearable health devices causing unnecessary and sometimes debilitating patient anxiety. Access to 24/7 real-time data can enable pathological symptom monitoring. In cases of wearables for conditions like atrial fibrillation, this compulsive monitoring can escalate into anxiety that is associated with higher symptom burden and worse quality of life.
While Apple is not currently offering immediate information on the level of real-time blood pressure readings, smartwatch notifications alone seemed to be enough to trigger the acute anxiety episodes in a 2020 atrial fibrillation case study. These notifications ultimately led to recurrent unnecessary and unproductive emergency room, urgent care, and provider visits. It’s possible that hypertension notifications could send some individuals into a similar spiral, despite Apple’s recommendation to simply bring up the notification at one’s next annual exam. It’s natural for individuals to seek immediate reassurance, and possibly unrealistic to expect them to cope until their next provider visit. Given the scale at which this feature is being deployed, healthcare systems could become strained by unnecessary visits.
However, Apple has taken steps to ensure minimal false positives, achieving a 92% specificity rate in validation trials. There is perhaps a greater concern that individuals with high blood pressure may find false reassurance in the absence of hypertension notifications. For individuals with Stage 2 Hypertension (a more severe condition), Apple’s notification feature failed to identify almost half of all cases. Postponing regular doctor’s visits under the illusion of health provided by a smartwatch could lead to worse health outcomes.
As health wearables continue to increase in popularity, it’s worth considering potential sources of unintentional harm and how they can be prevented. This sentiment isn’t limited to blood pressure monitoring. Alongside hypertension notifications, Apple released a sleep scoring system despite a growing body of research suggesting that sleep-tracking wearables may have a negative psychological impact on people with sleep disorders such as insomnia. They may even lead people to develop the disorder. It seems there is a very fine line between technology that can promote health or detract from one’s quality of life, and that line is largely individual. Evidence seems to point to the fact that wearables aren’t for everyone.